Shoe and method of fixing shoe stiffeners in position therein



Oct. 7, 1930. H. H. BEcKwrrH 1,777,544

SHOE AND METHOD OF FIXING SHOE STIFFENERS IN POSITION THERIN .Filed VJuly L7, 1924 been fixed in position of this invention Patented Oct.` 7, 11930 UNITED STATES PATENT OFFICE j HARRY` H. BECKWITH, OF BROOKLINE, MASSACHUSETTS Application mea July-7, 1924. serial 116.724,560.

Toe stiffeners for shoes have commonly by being stitched to the upper prior to the 'lasting operation, or by the use-of a cement such as rubber cement, 0r in case of stiiieners formed of `librous sheet material saturated with thermoplastic material, by thermoplastic material exuded therefrom by subjecting the parts to be unitedito' heat and pressure.

The adhesives heretofore used haven-been somewhat unsatisfactory, either employing a volatile solvent which often penetrates the leather of the upper andstains it or necessitating the use of heat or heat and pressure. The solvents have been expensive and often dangerous and the adhesion has not been entirel satisfactory.

Tiife present invention relates to the use of rubber in the form of an aqueous dispersion such as'natural or artificial latex for the adhesive material. By the use of this material a very close adhesion oi the parts is readily' effected without the use of heat treatment and Without danger ofstaining the leather. The stidener blank, the shoe lining, or the leather upper, has a smear of latex ap lied thereto, the parts are then assembled w ile the latex is tacky and pressure is a plied under atmospheric temperatures, an union of the parts of a high order of strength is obtained'. l'This operation is no wise comparable to sticking with rubber cement. The attachment is much rmer when the latex is emploed and there is no penetration of the leat er or upper which 1s dicult to avoid when cements containing a rubber-.solvent are' used.

There are available suspensions of rubber inA water quite comparable tomatural latex in that no rubber solventis present, and such suspensions may be employed in the practice in thesame 'manner as the natural latex. The term latex as. used in this application is therefore intended to cover these artilicial suspensions `as `we1l as the natural latex.. i l

. For a more complete understanding of this invention reference may be had to the accompanying drawings in which 'f Figure l is a perspective of a toe stiener v blankA Figure 2is a fragmentary plan of the toe portion of a shoe upper having the blank incorporated therein.

Figure 3 is a section on ure 2.

Figure 4 is a fragmentary perspective line 3-3 of Fig- Figure 6 is a section somewhat similar' to Figure 3, but illustrating a" modification.

` A toe stiiener blank such as is shown at 1 in Figure 1 is to be fixed to the portions of a. shoe upper, as shown in Figure 3, in which 2 indicates the toe piece which is attached along `its rear edgeas by stitching lines 3 to the forward portion of the cut vamp 4. At 5 is shown the lining of the shoe and at 6' a doubler. v The rear edge of the blank 1 which is formed thin, as shown at 7, is i-nsertedbetween the forwardly projecting edge 8 of the vamp and the toe piece, after the toe stiffeuer, the toe piece 2 or theldoubler, or any of these parts, ing of the latex. The latex may sired,.or it `may be applied onl adjacent to its rear edge.` The parts are t en subjected to pressure under atmospheric temperature to secure adhesion. I

Beside the advantage of prompt and .etlihave been smeared with a coat-v` be appliedv over the entire surface of the stiener if de` cient sticking of the parts there are collateral advantages in the use of latex as an adhesive material. YFor example, rubber-covered toe parte are much more safe from cracking by exure than .when'no such rubber is present. Also if 4the blank is formed of fibrous material saturated .with a thermoplastic stiening' agent and the thinner parts of the blank nearer the inste be covered with rubber in this manner tige subsequent heating and molding of the box in the lasting operation, as illustrated in Figures 4 and 5, causes a portion of the thermoplastic material to iow forwardly toward the toe portion of the shoe, as shown at IOinFigures 4 and 5, and the rub ber covering of the stiener thereto prevents the Ithermoplastic material being impervious from exuding therefrom. This will'be apparent from an inspection of Figures 4 and 5 in which it will be seen that the forces exerted when the upper is pulled into position during the lasting operation, as shown by the arrows, causes considerable pressure to be exerted be`- tween the upper and the last over the rear portions of the stifl'ener and a. concentration of the fibrous material where the blank is gathered together over the curve of the toe as at 10. The thermoplastic material in the stiffener is thus squeezed forward so that it is somewhat impoverished along its rear edge where flexibility is desirable and is present in a greater amount even relative to the amount of fibrous material at the curve of the toe, as at 10, where maximum stiffness and hardness is desirable. When the part-s are permitted to cool after the lasting operation, therefore, the maximum stiffness is at the curve 10 where it is most desirable and the rear portion of the stiffener is f'lexible, which is also desirable.

The heating of the stiffener and adjacent parts inA order to soften the thermoplastic so that the stiffener may be shaped tothe last in the lasting operation, also causes the rubber tol become more tacky, the temperatures used being, however, insufficiently high to cause breaking down of the rubber.

Any suitable thermoplastic compound is employed as the stiffening agent for the box ,toe which will soften at such moderate temy doubler and fixing both the stiflener and the doubler firmly tothe under face of the toe piece 2.

Where a Separate toe piece stitched to the vamp is employed, as is shown in Figures 3 and 6, the use of the latex causes the forwardly projectin edge portion 8 of the vamp to be firmly held against wrinkling, which is a difiiculty often experienced in shoes made up in this manner where other methods of fixing the toe stifener in position have been employed. Of course the toe piece might be integral with the vamp if desired.

Having thus described this invention, what is claimed is:

1. The method which comprises coating with latex a shoe stiffener comprising a terial, incorporating the coated stiffener in a lib shoe upper while the latex is tacky and pressmg it into close union therewith, heating the parts to soften the thermoplastic material to permit it to flow within the stifener, and then lastin in the up er. l l

2. he metho of attaching shoe parts comprising a shoe upper and a stiffenerfibrous material saturated with a thermoplas-l tic, said stiffener being united to said upper by rubber, said upper being free from rubbersolvent stains and the bond between the stiffener and upper having the great Atenacity characteristic of the rubber having been applied in the form of latex.

5. A shoe comprising an upper having incorporated therein a stiffener comprising fibrous sheet material saturated with a thermoplastic and united to said upper by rubber,

said upper being free from rubber-solvent stains and the bond between the stifener and upper having the great tenacity characteristic of the rubber having been applied in the form of latex, said rubber coating the stifener and sealing the thermoplastic therein.

6. A vshoe comprising an upper having incorporated therein a stiffener comprising fibrous sheet material saturated with a. thermoplastic and united to said upper by rubber,

said upper being free from rubber-solvent stains and the bond between the stifl'ener and upper having the great tenacity characteristic of the rubber having been applied in the form of latex, said rubber coating the stifi'ener and sealing the thermoplastic therein the amount of thermoplastic being relatively great at the forward portion of said stifl'ener and relatively small adjacent to its rearvedge.

7. A shoe comprising an upper having incorporated therein a stifener comprising fibrous sheet material saturated with a stiffening agent, said stifener being coated with rubber which also bonds said stiffener with said upper, the proportion of stifl'ening agent to fibrous material being greater at the forward portion of the stifi'ener than rearwardly thereof.

In testimony whereof I have afiixed my signature. p

HARRY H. BECKWITH. 

